In recent years, CMOS image sensors easily adaptable to common semiconductor manufacturing techniques have become mainstream in the field of image sensors, and the number of pixels is being further increased and the sensitivity is becoming higher. Like a CCD image sensor, a CMOS image sensor uses a photodiode formed in a silicon substrate, as a photoelectric conversion element. In this case, a reduction in pixel size with an increase in the number of pixels exposes the problem that the incident photon-to-current conversion efficiency is degraded due to an interconnect layer located above the photodiode.
For this reason, Patent Literature (PTL) 1 (Japanese Unexamined Patent Application Publication No. 2012-19169) proposes a new image sensor (photoelectric conversion film layered image sensor) in which the photoelectric conversion element (photoelectric conversion film) is formed on lines instead of in the silicon substrate.